Department of Orthopaedic Surgery, Ashikaga Red Cross Hospital, 284-1 Yobe-cho, Ashikaga, 326-0843, Tochigi, Japan.
BMC Musculoskelet Disord. 2024 Jun 8;25(1):456. doi: 10.1186/s12891-024-07572-1.
Osteosynthesis using antegrade intramedullary nailing for humeral shaft fractures yields satisfactory bone union rates; however, it may adversely affect postoperative shoulder function. To date, factors affecting mid- or long-term shoulder functional outcomes following intramedullary nail fixation have not been clarified. In this study, we aimed to identify the risk factors for poor mid-term functional outcomes over 5 years postoperatively following antegrade intramedullary nail osteosynthesis for humeral shaft fractures.
We retrospectively identified 33 patients who underwent surgery using an antegrade intramedullary nail for acute traumatic humeral shaft fractures and were followed up for at least 5 years postoperatively. We divided the patients into clinical failure and no clinical failure groups using an age- and sex-adjusted Constant score of 55 at the final follow-up as the cutoff value. We compared preoperative, perioperative, and postoperative factors between the two groups.
Five of the 33 patients had poor shoulder functional outcomes (adjusted Constant score < 55) at a mean follow-up of 7.5 years postoperatively. Proximal protrusion of the nail at the time of bone union (P = 0.004) and older age (P = 0.009) were significantly associated with clinical failure in the univariate analyses. Multivariate analysis showed that proximal protrusion of the nail (P = 0.031) was a risk factor for poor outcomes.
The findings of this study provide new information on predictive factors affecting mid-term outcomes following osteosynthesis using antegrade nails. Our results demonstrated that proximal protrusion of the nail was significantly associated with poor mid-term functional shoulder outcomes. Therefore, particularly in older adults, it is essential to place the proximal end of the intramedullary nail below the level of the articular cartilage.
顺行髓内钉固定治疗肱骨干骨折的骨愈合率令人满意，但可能会对术后肩部功能产生不利影响。迄今为止，影响髓内钉固定后中、长期肩部功能结局的因素尚未明确。本研究旨在确定顺行髓内钉固定肱骨干骨折术后 5 年以上中、长期功能结局不良的危险因素。
我们回顾性分析了 33 例采用顺行髓内钉治疗急性创伤性肱骨干骨折的患者，术后随访至少 5 年。我们根据最终随访时年龄和性别调整的Constant 评分（截取值为 55）将患者分为临床失败组和无临床失败组。我们比较了两组患者的术前、围手术期和术后因素。
33 例患者中有 5 例在术后平均 7.5 年随访时肩部功能不良（调整后的 Constant 评分<55）。骨愈合时钉的近端突出（P=0.004）和年龄较大（P=0.009）在单因素分析中与临床失败显著相关。多因素分析显示，钉的近端突出（P=0.031）是预后不良的危险因素。
本研究结果为影响顺行钉固定后中期结果的预测因素提供了新信息。我们的结果表明，钉的近端突出与中期肩部功能结局不良显著相关。因此，特别是在老年人中，必须将髓内钉的近端置于关节软骨以下。
